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FXUS06 KWBC 021902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU OCTOBER 02 2025
6-10 DAY OUTLOOK FOR OCT 08 - 12 2025
THE GEFS, ECENS, AND CMCE ARE IN GOOD AGREEMENT THAT A 500-HPA RIDGE BUILDS
OVER MAINLAND ALASKA DURING THE 6-10 DAY PERIOD BUT DIFFER ON ITS STRENGTH AND
POLEWARD AMPLIFICATION. THESE TWO FACTORS WILL BE CRITICAL IN HOW MUCH OF A
DOWNSTREAM TROUGH STRENGTHENS ALONG THE WEST COAST. THE ENSEMBLE MEAN SOLUTIONS
FEATURE A BROAD 500-HPA RIDGE OVER THE CENTRAL AND EASTERN CONTIGUOUS U.S.
(CONUS) WITH THE ECENS HAVING THE LARGEST POSITIVE 500-HPA HEIGHT ANOMALIES
(+60 METERS OR MORE) WITH THIS RIDGE. THE 0Z AND 6Z GEFS ARE OUTLIERS WITH A
DEVELOPING MID-LEVEL TROUGH OVER EASTERN CANADA AND THIS FEATURE WAS ABSENT IN
PREVIOUS GEFS MODEL RUNS. THEREFORE, THE MANUAL 500-HPA HEIGHT MANUAL BLEND WAS
WEIGHTED MOST HEAVILY WITH THE ECENS AND CMCE SOLUTIONS.
DESPITE THE EXPECTATION FOR AN AMPLIFYING 500-HPA RIDGE UPSTREAM OVER ALASKA
WHICH CAN TYPICALLY LEAD TO AN OUTBREAK OF COLDER-THAN-NORMAL TEMPERATURES FOR
THE LOWER 48 STATES, NEAR TO ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR THE
ENTIRE CONUS. THIS MILD TEMPERATURE PATTERN IS DUE TO THE LACK OF ANY SUSTAINED
ANOMALOUS NORTHERLY FLOW AT THE MID TO HIGH LATITUDES OF NORTH AMERICA THROUGH
MID-OCTOBER. NEAR-NORMAL TEMPERATURES ARE MOST LIKELY ACROSS PARTS OF THE GREAT
LAKES, NORTHEAST, CALIFORNIA, AND NEVADA WHERE TEMPERATURES ARE PREDICTED TO BE
MORE VARIABLE DURING THIS 5-DAY PERIOD. BASED ON THE PREFERRED ECENS AND CMCE
WITH SUBSTANTIAL, ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE LARGEST (MORE THAN
60 PERCENT) FOR MUCH OF TEXAS AND WESTERN GULF COAST.
THE NATIONAL HURRICANE CENTER (NHC) IS MONITORING A TROUGH OF LOW PRESSURE A
FEW HUNDRED MILES OFFSHORE OF SOUTHWESTERN MEXICO. AS OF 11AM PDT ON OCTOBER 2,
THE NHC STATES THAT THERE IS A 70 AND 90 PERCENT CHANCE OF TROPICAL CYCLONE
(TC) DEVELOPMENT ACROSS THE EAST PACIFIC DURING THE NEXT TWO AND SEVEN DAYS,
RESPECTIVELY. THIS POTENTIAL TC IS LIKELY TO TRACK NORTHWESTWARD TOWARDS THE
BAJA PENINSULA BY EARLY NEXT WEEK. MODEL SPREAD REMAINS LARGE ON ITS FINAL
TRACK LATER NEXT WEEK WITH THE OUTCOMES RANGING FROM A DISSIPATING LOW WELL
OFFSHORE OF THE BAJA PENINSULA TO A REMNANT LOW TRACKING INTO SOUTHEASTERN
CALIFORNIA AND SOUTHWESTERN ARIZONA. DESPITE THIS HIGH FORECAST UNCERTAINTY,
ANOMALOUS LOW TO MID-LEVEL MOISTURE IS EXPECTED TO SHIFT NORTHWARD FROM THE
EAST PACIFIC AND WITH AN AMPLIFYING 500-HPA TROUGH NEAR THE WEST COAST,
ABOVE-NORMAL PRECIPITATION IS FAVORED FOR THE WESTERN CONUS. THE LARGEST
ABOVE-NORMAL PRECIPITATION PROBABILITIES (EXCEEDING 60 PERCENT) ARE FOCUSED
ACROSS THE DESERT SOUTHWEST WHERE THE REMNANTS OF AN EAST PACIFIC TC COULD HAVE
ITS GREATEST IMPACT AND CLIMATOLOGY IS LOWER. BROAD SURFACE HIGH PRESSURE,
PREDICTED BY ALL THE ENSEMBLE MEAN SOLUTIONS, IS EXPECTED TO RESULT IN NEAR TO
BELOW-NORMAL PRECIPITATION FROM THE GREAT PLAINS EAST TO THE OHIO AND TENNESSEE
VALLEYS. ON DAY 6, A COLD FRONT IS FORECAST TO CROSS THE EASTERN CONUS WHICH
TILTS THE OUTLOOK TOWARDS THE WET SIDE. EASTERLY FLOW AND A BREAK IN THE
SUBTROPICAL RIDGE SUPPORTS AN INCREASED CHANCE OF ABOVE-NORMAL PRECIPITATION
ACROSS THE FLORIDA PENINSULA AND SOUTHERN TEXAS.
FORECAST CONFIDENCE IS HIGH ACROSS ALASKA WITH MODELS REMAINING CONSISTENT THAT
A HIGHLY AMPLIFIED TROUGH CENTERED OVER THE KAMCHATKA PENINSULA LIKELY SPAWNS A
PAIR OF LOW PRESSURE SYSTEMS TRACKING INTO THE BERING SEA. THESE LOW PRESSURE
SYSTEMS AND ASSOCIATED ONSHORE FLOW FAVOR ABOVE-NORMAL TEMPERATURES AND
ABOVE-NORMAL PRECIPITATION FOR MUCH OF ALASKA. THE ONE EXCEPTION TO THE WET
PATTERN IS SOUTHEASTERN ALASKA WHICH WOULD BE DOWNSTREAM OF THE 500-HPA RIDGE
AXIS AND LEADS TO AN ELEVATED CHANCE OF BELOW-NORMAL PRECIPITATION.
BASED ON THE GEFS AND ECENS, ABOVE-NORMAL TEMPERATURES AND ABOVE-NORMAL
PRECIPITATION ARE FAVORED FOR HAWAII.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 20% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 45% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 35% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE TEMPERATURE TOOLS BUT REDUCED SLIGHTLY DUE TO
CONTINUED LARGE MODEL SPREAD ON THE FINAL TRACK OF A POTENTIAL TC IN THE EAST
PACIFIC.
8-14 DAY OUTLOOK FOR OCT 10 - 16 2025
THE PREFERRED ECENS AND CMCE ARE IN GOOD AGREEMENT MAINTAINING A HIGH AMPLITUDE
500-HPA RIDGE OVER THE GULF OF ALASKA AND EASTERN MAINLAND ALASKA, WHILE THE
GEFS DEPICTS THIS RIDGE RAPIDLY WEAKENING LATER IN WEEK-2. DOWNSTREAM CLOSER TO
AND OVER THE CONUS, THESE ENSEMBLE MEANS ARE IN REASONABLY GOOD AGREEMENT WITH
A MID-LEVEL TROUGH OF VARYING AMPLITUDE NEAR THE WEST COAST AND A BROAD 500-HPA
RIDGE ACROSS THE CENTRAL AND EASTERN CONUS. DESPITE THE OVERALL GOOD AGREEMENT
IN THE 7-DAY MEAN HEIGHT FIELDS, DAILY FORECASTS LATER IN WEEK-2 REVEAL
DIVERGING MODEL SOLUTIONS ON THE LONGWAVE PATTERN. THE BROAD RIDGE WITH
POSITIVE 500-HPA HEIGHT ANOMALIES SUPPORTS AN INCREASED CHANCE OF ABOVE-NORMAL
TEMPERATURES FOR THE EASTERN TWO-THIRDS OF THE CONUS. ALSO, THE SOURCE REGION
AT THE HIGHER LATITUDES OF NORTH AMERICA IS LIKELY TO HAVE ABOVE-NORMAL
TEMPERATURES HEADING INTO WEEK-2 DUE TO THE PROLONGED PACIFIC FLOW. THE
MID-LEVEL TROUGH ALOFT WITH CORRESPONDING NEGATIVE 500-HEIGHT ANOMALIES FAVORS
NEAR TO BELOW-NORMAL TEMPERATURES ACROSS THE NORTHERN ROCKIES, PACIFIC
NORTHWEST, GREAT BASIN, AND CALIFORNIA.
THE WEEK-2 PRECIPITATION OUTLOOK GENERALLY FOLLOWED THE UNCALIBRATED ECENS.
BROAD SURFACE HIGH PRESSURE ALONG WITH THE LIKELIHOOD THAT THE STORM TRACK IS
DISPLACED NORTH OF ITS TYPICAL LOCATION FOR MID-OCTOBER FAVORS NEAR TO
BELOW-NORMAL PRECIPITATION FOR MUCH OF THE EASTERN AND SOUTH-CENTRAL CONUS. THE
OUTLOOK SLIGHTLY LEANS TOWARDS THE WET SIDE ACROSS THE COASTAL SOUTHEAST AND
FLORIDA PENINSULA DUE TO A BREAK IN THE SUBTROPICAL RIDGE AND TENDENCY FOR
FRONTS TO STALL NEAR THE SOUTHEAST. AN AMPLIFIED 500-HPA TROUGH, NEAR THE WEST
COAST, SUPPORTS AN INCREASED CHANCE OF ABOVE-NORMAL PRECIPITATION ACROSS THE
WESTERN AND NORTH-CENTRAL CONUS. ABOVE-NORMAL PRECIPITATION PROBABILITIES ARE
MAXIMIZED FOR THE SOUTHWEST WHERE CLIMATOLOGY IS LOWER AND THAT REGION COULD BE
INFLUENCED BY EAST PACIFIC TCS.
SIMILAR TO THE 6-10 DAY PERIOD, SOUTHWESTERLY ONSHORE FLOW STRONGLY FAVORS
ABOVE-NORMAL TEMPERATURES THROUGHOUT ALASKA. THE ENHANCED ONSHORE FLOW ALSO
SUPPORTS AN INCREASED CHANCE OF ABOVE-NORMAL PRECIPITATION FOR MUCH OF MAINLAND
ALASKA. DOWNSTREAM OF THE MID-LEVEL RIDGE AXIS, NEAR TO BELOW-NORMAL
PRECIPITATION IS MORE LIKELY FOR SOUTHEASTERN ALASKA.
BASED ON THE GEFS AND ECENS, ABOVE-NORMAL TEMPERATURES AND ABOVE-NORMAL
PRECIPITATION ARE FAVORED FOR HAWAII. POSITIVE SEA SURFACE TEMPERATURE
ANOMALIES ALSO SUPPORT ABOVE-NORMAL TEMPERATURES, ESPECIALLY ACROSS THE
NORTHWESTERN ISLANDS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 20% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 45% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 35% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO
DIVERGING MODEL SOLUTIONS ON THE EVOLVING LONGWAVE PATTERN LATER IN WEEK-2.
FORECASTER: BRAD PUGH
NOTES:
THE NOTATION FOR THE CATEGORICAL FORECAST INDICATED ON THE MAPS IS THE SAME AS
THAT IN THE TABLES: A-ABOVE N-NEAR NORMAL B-BELOW
THE TEMPERATURE MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WARMER (ORANGE,
"A"), COLDER (BLUE, "B"), OR CLOSE TO (UNSHADED, "N"). HISTORICAL AVERAGE
VALUES FOR THE CALENDAR PERIOD OF THE FORECAST (DASHES, "F"). LABELS ON THE
SHADED LINES GIVE THE PROBABILITY (> 33%) OF THE MORE LIKELY CATEGORY (B OR A).
PROBABILITY OF N IS ALWAYS < 40%.
THE PRECIPITATION MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WETTER (GREEN,
"A"), DRIER (TAN, "B"), OR CLOSE TO (UNSHADED, "N"). HISTORICAL MEDIAN VALUES
FOR THE CALENDAR PERIOD OF THE FORECAST (DASHES, "INCHES"). LABELS ON THE
SHADED LINES GIVE THE PROBABILITY (> 33%) OF THE MORE LIKELY CATEGORY (B OR A).
PROBABILITY OF N IS ALWAYS < 40%.
IN THE SOUTHWEST AND OTHER CLIMATOLOGICALLY DRY REGIONS - THERE WILL BE A
GREATER THAN 33.3% CHANCE OF NO PRECIPITATION AND OCCASIONALLY EVEN A NORMAL
(I.E. MEDIAN) VALUE OF ZERO - ESPECIALLY DURING THE DRY SEASONS. IN SUCH CASES
A FORECAST OF NEAR NORMAL IS EFFECTIVELY A FORECAST OF LITTLE OR NO
PRECIPITATION.
THE CLIMATE PREDICTION CENTER USES 1991-2020 BASE PERIOD MEANS AS REFERENCE IN
THE CLIMATE OUTLOOKS.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON
OCTOBER 16.
ANALOGS TO THE 5 DAY MEAN OBSERVED PATTERN CENTERED 3 DAYS AGO (D-3)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
20071008 - 20040919 - 19621002 - 20010928 - 19981012
ANALOGS TO THE 7 DAY MEAN OBSERVED PATTERN CENTERED 4 DAYS AGO (D-4)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 7 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
20071008 - 19621002 - 20040920 - 20010928 - 20071013
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 08 - 12 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF N A
SRN CALIF N A IDAHO A A NEVADA N A
W MONTANA A A E MONTANA A N WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A A N DAKOTA A N S DAKOTA A N
NEBRASKA A N KANSAS A N OKLAHOMA A B
N TEXAS A N S TEXAS A N W TEXAS A A
MINNESOTA A N IOWA A N MISSOURI A B
ARKANSAS A B LOUISIANA A N WISCONSIN A N
ILLINOIS A B MISSISSIPPI A B MICHIGAN N B
INDIANA A B OHIO N N KENTUCKY A N
TENNESSEE A N ALABAMA A N NEW YORK N N
VERMONT N N NEW HAMP N A MAINE N A
MASS N A CONN N A RHODE IS N A
PENN N N NEW JERSEY N A W VIRGINIA N N
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA A A S CAROLINA A A GEORGIA A N
FL PNHDL A N FL PENIN A A AK N SLOPE A A
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A B AK PNHDL A B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 10 - 16 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B A NRN CALIF B A
SRN CALIF N A IDAHO N A NEVADA N A
W MONTANA N A E MONTANA N A WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A A N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A N OKLAHOMA A N
N TEXAS A N S TEXAS A N W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A N
ARKANSAS A B LOUISIANA A B WISCONSIN A A
ILLINOIS A N MISSISSIPPI A B MICHIGAN A N
INDIANA A N OHIO A N KENTUCKY A B
TENNESSEE A B ALABAMA A B NEW YORK A B
VERMONT A N NEW HAMP A N MAINE A N
MASS A N CONN A N RHODE IS A N
PENN A B NEW JERSEY A N W VIRGINIA A B
MARYLAND A N DELAWARE A N VIRGINIA A N
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A A AK N SLOPE A A
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A B
LEGEND
TEMPS WITH RESPECT TO NORMAL PCPN WITH RESPECT TO MEDIAN
A - ABOVE N - NEAR NORMAL A - ABOVE N - NEAR MEDIAN
B - BELOW B - BELOW
THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE.
FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS
PMDMRD.
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